With the development of science and technology, liquid crystal display technologies become more and more mature; and for a TV set, it also changes from the traditional display tube to the current liquid crystal display screen. The liquid crystal display screen is an inactive light-emitting display screen, which does not emit light itself, thus the liquid crystal display screen requires a backlight module to provide a light source. The backlight module has a good colour reducibility, and it is may be easily controlled divisionally, thus it has become the predominant backlight source for a liquid crystal display screen. According to its position in the liquid crystal display screen, the backlight module may further be divided into side-edge type backlight module and direct-type backlight module. Because a light guide plate is used, the side-edge type backlight module may be made ultrathin. As the lightening and thinning of a liquid crystal TV is becoming a main steam in the market today, the side-edge type backlight module for a liquid crystal screen is widely used.
However, the brightness and contrast of a liquid crystal display screen are poor all along. Because that the liquid crystal does not emit light itself and a luminescent tube is required behind a liquid crystal panel to provide a light source, when a poor shielding exists, light leakage may occur, and the contrast and brightness of the liquid crystal display screen will be influenced. For a light guide plate and a plastic frame that do not have a shielding structure, the light outgoing from the side edge of the light guide plate will be reflected by the edge of the plastic frame and emit from the gap between the light guide plate and the plastic frame, which causes a problem that light leakage or bright line appears at the edge of the backlight source module. At present, a light beam emitted from the gap between the light guide plate and the plastic frame is usually shielded by a printed black edge of a diffuser. However, because a gap exists between the diffuser and the plastic frame, it cannot attain the effect that no light is leaked, and the light beam at the edge will still be reflected in the gap, thus light leakage will appear, the light shielding effect will be unapparent, and production cost will be increased.
Therefore, as directed to the above defects, it requires a light guide plate and a forming mould and a manufacturing method thereof, a backlight module, and a display device, which have an apparent light shielding effect, thereby the problem of edge light leakage and edge bright line can be effectively prevented, moreover, the light utilization may be improved, and the production cost may be lowered.